Method of producing toilet soap



Jan. 10, 1950 Filed Dec. 6, 1946 J. K. o. H. HOLMBERG 2,

METHOD OF PRODUCING TOILET SOAP 2 Sheets-Sheet 1 Jan. 10, 1950 J. K. o. HOLMBERG 2,494,127

METHOD OF PRODUCING TOILET SOAP Filed Dec. 6, 1946 2 Sheets-Sheet 2 Patented Jan. 10, 1950 2551 .127 METHOD onmonoomcemomnr soan JohnKarlJQslrar Huhertllolmhesg we e mm Application December: 6, 194 3 I111 Sweden Ilecembhnflfilfifit e seamen-4,533":

syoia'ii ns. (o1. nears This, invention relates. to. a. new and. useful.

method in the saponificationoi fattyacidae'stersgj for, the; production of milled toiletsoaps.

Such. soaps, have. hitherto been produced by; saponifying glycerides of fatty. acids. m ax s of,- caustic alkali dissolved.- in v water. or: alcohol...

Generally the saponification is carried out in opem.

vessels; for which reason. thereaction. tempera tnresmustberkept below 100 C., so that the water;

isnoLboiledofi. After the saponification "the:

will haveto; be diluted with water. beforethe milling operation. A process of thiskind. is claimed in, the U. S. Patent.No..2,08&,5i46, granted. tQEI-Ienry-W. F. Lorenz.

According to Lorenz the saponification. of; glycerides. or. other esters of fatty acids. iscarried.

out at. a temperature. above theJmelting, point; on the resulting anhydrouslsoap: and. in. anatmosr. Dhere. freeof. air while. intimately contacting,'tlie mixture. with. a. stream. of; superheated water." vapour... The. high saponification temperature;

accordingv to Lorenz brings. about. the. disade' vantage. of higher costs and the. risk; of localfg.

superrheatings, resulting. in damages ofjthe prod;- uct. The, blowing of, steam throu h the mass. always. causes av loss. of "fatty materials. distillable. with water vapor and thus a decrease intheyieldii oisoap... Finally the soap mass obtainedatter:

wards must bediluted withwater bef one the can be, milledto toilet soap, this mixing.,. as.well; known, being a rather seriousoperation...

The-present invention consists-in anewmethml for the saponification, resulting in a soap mass of a. consistency which makesitzdirectly milleable for the production of toilet soaps... As. starting. material for the process of the. invention I. use. certain alcoholic esters of fatty acids, namely'such esters of which the alcohols have a lower boiling point-than water under the saponificatiomcone ditions. Suchesters according; tmmy invention aresaponified. with alkali, preferably; caustic alkali in the presence of a di1uent.1such asvwater or alcohol ora mixture of water'and alcoholin such: aquantitythat the diluent remaining; after saponification will suffice for making the soap mass milleable, the saponification being carried rec rerin-g this alcohol.

2 ontiaizta temperature suitably below 125 which theacharge-is semiliq uidto: liquid;

As has been statedwabove the alcohols. Qf-thfijr.

esters-t. used. as; starting material must. be,- of the havingalower boiling point, than water. at;v v ail ng, saponification conditions. Such; ale, o are;for-instancetmethanol, ethanolancl-t p v anol .ot which; the, methanol: esters.- are: E len-r fern .d due. to vthe simpler and cheaper. methods-0t perature; that; the: mass; isfliquid. Further, the temperature. musttbe. above the. boiling point: of. theialooholoi the-Elston. Byusine suehtemperature the alcohol liberated during the-saponifica. tioniis boiledofi and maybe recovered by known methods.

According to. a. preferred, embodiment the.

saponificationt is carried. out. in a still pot; ro-t 2o, vided with-stirring meansand. a fractionating;

columnr Eva-constructing. the fractionating cokumngwith. a; sufficient. number. of plates. and by: usingassnitable reflux ratio it. ispossibleto-obtain, aesnbstantially concentrated. alcohol and. simulr taneouslvto maintain. sucha Water. contentin the: note-that?they-resulting soap is directly. milleable However if...' theasoap; isv tobe. completely freed froizianvtraces.ofthealcohol .onecannot prevent. .311

being multaneously distilledoff. If desired the. correct. water content of the mass couldbe adrjnstedbw. additionrof. water: towards. the. endoi, thesaponiiication process,

The... oal stlcnalkalihuseifor the saponification. QOnltIZZbQaddedeither at once. from ,the beginning or inportions-during the process. It is, also, pose sibleto; addithe .alkaliinsolid form .or as. a con: centrateld,l.solution, the. water. content of. possibly together with otherwise added. Water; mustnot .decreasathe. quantity of water required fonniakin thesoapmilleable.

. Inthe;tollowinethe. process... of the. invention. willilbemore. fully described in. anhexample. using, m yliiesters,.of fatty. acids-.as. starting. material; .andlwithreference to the, accompanying draw- Fig-J. 1; shows. more. or. less. dia rammatically at. etween Qiltlie tynelhit to, s butfitted 'vvitli.v

I As has-been stated above therreaoti on is to. be. carried out, at: so; highattem of the water ofthe order of aiew percent;

openings 4 and a discharge 5 for the vapours developed are arranged in the cover 6 of the saponification vessel. The methyl esters and the alkali are introduced into the reaction vessel I where they are intimately mixed while being heated. When the saponification reaction has started the heating is gently continued and si multaneously small quantities of water are added in order to maintain the liquid consistency of the" soap mass. When the saponification is finished the remaining liberated methanol is driven ofi" preferably while evacuating thereactionvessel If esters of higher boiling alcohols are used as starting material it is often suitable'to carry through the whole saponification reaction'below atmospheric pressure for the purpose- 'of.main-y taining the reaction temperature atLreasonabl .1;

values. Conversely in some cases it is advisable to carry out the reaction at a pressure above atmospheric in order to accelerate the reaction or improve the yield. When the saponificaition is completed the excess alkali may be neutralized by the addition of free fatty acids.

' According to the improved embodiment of the invention illustrated by the apparatus of Fig. 2 the introduction of the starting materials is carried out as described above. During the reactionvapours of water and alcohol, for instance methanol, are evolved, passing through the discharge pipe 5 into a fractionating column 1, from which the reflux is returned to the reaction vessel I through a pipe 8. The fractionating column is further provided with coolers 9 and reflux dividers" 10, known per se, from which the concentrated alcohol is discharged. "'5' Exam ner-The apparatus is charged with 1000 kg. methyl ester of palm oil fatty acids (saponification No. 215). The esters are heated to 100 C. and about half of the required alkali, viz. '75 kg. caustic soda in anhydrous form is added while vigorously stirring. The soap formed is dispersed in the molten ester, the charge still being liquid.- When the rest of the alkali, '7'? kg, is added it is also necessary to add water (totalling 100-200 kg), and to raise the temperature to about 120- 125 C. in order to maintain the liquid condition,

The new saponification method according to; the invention makes it possible to produce a toilet soapwith a desired free alkali content, very low salt content (originating only from impurities in the caustic alkali used for the saponificationfl and finally an adjustable water content making the soap readily milleable. Contrary to the previous saponification processes my improved proc; ess results in a milleable toilet soap mass in one single step. The alcohol liberated during the saponification can be easily recovered and further salts, solvents, alcohols, suitably fattyalcohols and sulphonated fatty alcohols.

Iclaim: 1. The method of producing a milleable soap directly with the saponification with ,alkaliof fatty acid esters of such alcohols that have a lower boiling point than water under the saponificatiori conditions employed, which method comprises saponifying such fatty acid esters with alkali in the presence of a liquid diluent for the soap and at a temperature at which the charge is from semi-liquid to liquid above the boiling point of the alcoholliberated from the esters and not in excess of about 125 C., said diluent being volatile under the saponifying'conditions and having a boiling point over that of the alcohol liberated from the esters, distilling off the alcohol liberated from the esters, and continuously fractionating the vapors evolved during the saponification as 'theyare evolved to rectify 01f the alcohol liberated from the starting ester and drawing it off separately while returning the diluent fraction as the reflux to the reaction mass, the diluent having been included in a quantity substantially equal to that desired in the soap produced and adjusted to that concentration so that after the removal of the liberated alcohol, the soap mass on cooling is directly milleable.

2. The method as claimed in claim 1, wherein the diluent is a hydroxyl-group-contain'ing material which is a member of the class consisting of water, ethanol, and a mixture of water and 'eth anol.

3. The method as claimed in claim 2, wherein the diluent is water and it is added to the reaction mass in such quantity that its content in the soap mass remaining after the saponification is completed is between about ten and about thirty percent.

4. The method as claimed in claim 3, wherein the quantity of water added is such that its content in the soap mass after the saponification is completed is between about ten and about twenty percent.

5. The method of producing a milleable soap directly with the saponiflcation with alkali ofthe methyl ester of palm oil fatty acids, which method comprises saponifying said fatty acid esters with caustic alkali in the presence of water as a diluent for the soap at a temperature raised to'between about and about C., distilling qif the methanol liberated from the esters, and continuously fractionating the vapors evolved during the saponification as they are evolved to rectify ofi the alcohol liberated from the starting ester and drawing it ofi separately while returning the diluent fraction as the reflux to the re-:

action mass, the water having been included in a quantitysufficient to give a concentration oi between about ten and about twenty percent in the finished soap and adjusting its content during the treatment so that after the methanol is distilled off, the soap mass on cooling contains be} tween about ten and about twenty percent of,

water and is directly milleable.

JOHN KARL OSKAR HUBERT HOLMBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,271,619 Bradshaw et al. Feb. 3, 1942 .2,360,844 Bradshaw et al Oct. 24, 19.44. 2,383,630 Trent Aug. 28, 1945 12,383,631 Trent Aug. 28, 1945 2,382,530 Auer Aug. 14, 1 945 

1. THE METHOD OF PRODUCING A MILLEABLE SOAP DIRECTLY WITH THE SAPONIFICATION WITH ALKALI OF FATTY ACID ESTERS OF SUCH ALCOHOLS THAT HAVE A LOWER BOILING POINT THAN WATER UNDER THE SAPONIFICATION CONDITIONS EMPLOYED, WHICH METHOD COMPRISES SAPONIFYING SUCH FATTY ACID ESTERS WITH ALKALI IN THE PRESENCE OF A LIQUID DILUENT FOR THE SOAP AND AT A TEMPERATURE AT WHICH THE CHARGE IS FROM SEMI-LIQUID TO LIQUID ABOVE THE BOILING POINT OF THE ALCOHOL LIBERATED FROM THE ESTERS AND NOT IN EXCESS OF ABOUT 125* C., SAID DILUENT BEING VOLATILE UNDER THE SAPONIFYING CONDITIONS AND HAVING A BOILING POINT OVER THAT OF THE ALCOHOL LIBERATED FROM THE ESTERS, DISTILLING OFF THE ALCOHOL LIBERATED FROM THE ESTERS, AND CONTINUOUSLY FRACTIONATING THE VAPORS EVOLVED DURING THE SAPONIFICATION AS THEY ARE EVOLVED TO RECTIFY OFF THE ALCOHOL LIBERATED FROM THE STARTING ESTER AND DRAWING IT OFF SEPERATELY WHILE RETURNING THE DILUENT FRACTION AS THE REFLUX TO THE REACTION MASS, THE DILUENT 